#ifndef THREADS_THREAD_H
#define THREADS_THREAD_H

#include <debug.h>
#include <list.h>
#include <stdint.h>
#include "threads/synch.h"

/* States in a thread's life cycle. */
enum thread_status
  {
    THREAD_RUNNING,     /* Running thread. */
    THREAD_READY,       /* Not running but ready to run. */
    THREAD_BLOCKED,     /* Waiting for an event to trigger. */
    THREAD_DYING        /* About to be destroyed. */
  };

/* Thread identifier type.
   You can redefine this to whatever type you like. */
typedef int tid_t;
#define TID_ERROR ((tid_t) -1)          /* Error value for tid_t. */

/* Thread priorities. */
#define PRI_MIN 0                       /* Lowest priority. */
#define PRI_DEFAULT 31                  /* Default priority. */
#define PRI_MAX 63                      /* Highest priority. */

/* A kernel thread or user process.

   Each thread structure is stored in its own 4 kB page.  The
   thread structure itself sits at the very bottom of the page
   (at offset 0).  The rest of the page is reserved for the
   thread's kernel stack, which grows downward from the top of
   the page (at offset 4 kB).  Here's an illustration:

        4 kB +---------------------------------+
             |          kernel stack           |
             |                |                |
             |                |                |
             |                V                |
             |         grows downward          |
             |                                 |
             |                                 |
             |                                 |
             |                                 |
             |                                 |
             |                                 |
             |                                 |
             |                                 |
             +---------------------------------+
             |              magic              |
             |                :                |
             |                :                |
             |               name              |
             |              status             |
        0 kB +---------------------------------+

   The upshot of this is twofold:

      1. First, `struct thread' must not be allowed to grow too
         big.  If it does, then there will not be enough room for
         the kernel stack.  Our base `struct thread' is only a
         few bytes in size.  It probably should stay well under 1
         kB.

      2. Second, kernel stacks must not be allowed to grow too
         large.  If a stack overflows, it will corrupt the thread
         state.  Thus, kernel functions should not allocate large
         structures or arrays as non-static local variables.  Use
         dynamic allocation with malloc() or palloc_get_page()
         instead.

   The first symptom of either of these problems will probably be
   an assertion failure in thread_current(), which checks that
   the `magic' member of the running thread's `struct thread' is
   set to THREAD_MAGIC.  Stack overflow will normally change this
   value, triggering the assertion. */
/* The `elem' member has a dual purpose.  It can be an element in
   the run queue (thread.c), or it can be an element in a
   semaphore wait list (synch.c).  It can be used these two ways
   only because they are mutually exclusive: only a thread in the
   ready state is on the run queue, whereas only a thread in the
   blocked state is on a semaphore wait list. */
struct thread
  {
    /* Owned by thread.c. */
    tid_t tid;                          /* Thread identifier. */
    enum thread_status status;          /* Thread state. */
    char name[16];                      /* Name (for debugging purposes). */
    uint8_t *stack;                     /* Saved stack pointer. */
    int priority;                       /* Priority. */
    int64_t time_to_sleep;              /* Time to sleep when timer_sleep() is called */
    
    /* Shared between thread.c and synch.c. */
    struct list_elem elem;              /* List element. */

#ifdef USERPROG
    /* Owned by userprog/process.c. */
    uint32_t *pagedir;                  /* Page directory. */

    bool normal_exit;                   /* if the process is a user process then if this finish
                                               by the syscall exit () */

    int exit_code;                      /* the exit code to end the actual user process */

    bool is_user_program;               /* if this thread wrapp a user program */

    int fd;                             /* This integer is aimed to set file descriptors*/

    struct list child_process;          /* Children process of this thread */

    struct thread *father;              /* Inmediate father of this thread */

    struct lock lock;                   /* Lock to do synchronization on this thread */

    void *min_stack_addrs;				  /* This is a pointer to the minimum address valid in
                                           the stack of this thread, only has sense if this
                                           thread executes a user program, otherwise is NULL */
    struct file* file;                  /* The file in disk that is loaded into this thread*/

    struct list ppof_table;             /* Per-process open-file list*/
#endif


#ifdef VM
    struct list supplemental_list;      /* This list contains the pages of this thread that aren't in
         									                 main memory, i.e they're in the back storage device
         									                 (swap partition, executable) */
    struct lock lock_st;                /* lock on this structure */
    
    struct list mf_table;               /* This list is used to keep track of the mapped files of
                                           this thread */
                                            
    uint32_t mmid ;                     /* This is the first descriptor for the mapped files into
                                           memory */
                                           
    void *max_cds_addr;                 /* The maximum address that the code segment or the data segment
                                            reachs */
                                            
    struct semaphore sema_pf;
#endif

    /* Owned by thread.c. */
    unsigned magic;                     /* Detects stack overflow. */
  };


/*
 * These are the data that a process must knows about his children
 */
struct child_process
  {
    tid_t pid_t;
    int exit_status;
    struct semaphore sema;
    struct list_elem elem;
  };

/* Structure representing entries in the per-process open-file table */
struct ppof
  {
    int fd;                         /* File descriptor*/
    struct file* filefd;            /* Pointer to the open file*/
    struct list_elem elem;          /* List element*/
  };
  
/* Structure representing entries in the per-process mapped-files table */
struct mapped_file
  {
    uint32_t mapid;
    struct file *file;
    uint8_t *addr;
    uint32_t size;
    struct list_elem elem;
  };

/* If false (default), use round-robin scheduler.
   If true, use multi-level feedback queue scheduler.
   Controlled by kernel command-line option "-o mlfqs". */
extern bool thread_mlfqs;

void thread_init (void);
void thread_start (void);

void thread_tick (void);
void thread_print_stats (void);

typedef void thread_func (void *aux);
tid_t thread_create (const char *name, int priority, thread_func *, void *);

void thread_block (void);
void thread_unblock (struct thread *);

struct thread *thread_current (void);
tid_t thread_tid (void);
const char *thread_name (void);

void thread_exit (void) NO_RETURN;
void thread_yield (void);

int thread_get_priority (void);
void thread_set_priority (int);

int thread_get_nice (void);
void thread_set_nice (int);
int thread_get_recent_cpu (void);
int thread_get_load_avg (void);

#endif /* threads/thread.h */
